Is the following working for you:
- From an app on macOS, copy the text to the clipboard
- Make sure you can paste it within the same app or in another app to make sure the text is in the clipboard
- In Flame, go to a Type node
- Add a layer >>> The layer should have a red outline, meaning it is in edit mode
- Open the context menu (the cursor must be over the layer’s bounding box when you open it)
- Select “Text” in the “Paste” submenu.
Your text should be pasted. If it is not, I would recommend trying what John suggested.